Effect of mycorrhiza, pseudomonas bacteria and humic acid on growth indices of bean (Phaseolus vulgaris L.)

IntroductionLegumes are very important source of protein after cereals. These plants are capable of biological nitrogen fixation and increasing soil fertility as cover crop or including in crop rotation and reducing soil erosion which improve sustainable agriculture. Increasing use of chemical fertilizer which has negative effect on soil structure which cause unbalance on physical and chemical propertied of soil which ultimately reduce nutrient element absorption. Nowadays due to environmental problems use of biological fertilizers are good substitutions. On the other hand biological fertilizer use improve soil fertility. Protein quantity and quality are basic nutritional problem. According to use of more than 85000 tones chemical fertilizers in legume cultivation in Iran. It is necessary to conduct correct and efficient inoculation for each legume crop in the country including bean, which is one of the important crop for human consumption. In most cases biological fertilizers are complementary of chemical fertilizers in a sustainable agriculture. The aim of this study was to compare the effect of interaction effect of mycorrhiza vesicular, Psodomonas bacteria and humic acid on yield and yield components of bean.
Material & MethodsMycorrhiza inoculation was prepared in soil science Lab in Tabriz University in sterile sandy loam. Bacterial inoculation Pseudomonas putida prepared in soil biology of Tabriz University. Humic acid extraction was done with method of Kay et al., (2004). For Seed bean Phaseolus vulgaris variety Cos-16 from agronomy and plant breeding department of Tabriz University which is resistant to drought. Soils for this experiment were collected from Khalat Poshan research station from 0 to 25 cm depth and passed through 4mm sieve after sun sterile method. Soil physical and chemical properties were estimated with standard methods. Each pot was filled with three kilogram sterile soil. Seventy gram of mycorrhiza inoculation was spread in 5 cm of top soil and then bacteria inoculation was added to soil just below the seeds. Humic acid extracted from vermicompost and applied to soil in the powder form in three levels, control (H0), 200 mg kg-1(H1), and 400 mg kg-1 (H2). Pots were place in green house at 25C. After treatment application 5 seeds were sown in each pots and pot moisture kept at 0.9 FC. Pots were irrigated with distilled water whenever needed. After 4 months plant roots and shoot properties and plant yield and yield components were estimated. This experiment was conducted in the form of factorial on the base of complete randomize block design in Tarbiat Moalem University of Tabriz. First and second factor were in two levels, control and applied for mycorrhiza (M0 and M1) and bacteria P. putida (S0 and S1) and humic acid in three levels control (H0), 200 mg kg-1 (H1) and 400 mg kg-1 (H2) in three replications. Data analysis was done with MSTATC and SPSS and mean comparison were done with LSD test for significance and figures drown with Excel 2007.
Results & DiscussionAnalysis of variance of data for plant height showed that interaction effects of humic acid and bacteria were significant at 1% level and mycorrhiza was significant at 5% level. Mean comparison of results showed that least plant height mean from interaction of humic acid and bacteria with S0H1 treatment with (28.58 cm) and the highest was (30.35cm) with S1H1 treatment. Analysis of variance showed that main effect of mycorrhiza were significant at 1% level and interaction effect of humic acid and bacteria at 5% level on shoot wet weight of bean. Analysis of variance for main effect of humic acid and mycorrhiza were significant at 1% level for shoot dry weight and main effect of bacteria and interaction effect of bacteria and mycorrhiza were significant at 5% level for shoot dry weight of bean. Analysis of variance showed that main effect of mycorrhiza and humic acid were significant at 1% level and interaction effect of mycorrhiza and humic acid at 5% level on root dry weight. Analysis of variance of Mycorrhiza and bacteria main effect on ratio of root dry weight to shoot were significant at 1% level and main effect of humic acid and interaction effect of humic acid and mycorrhiza were significant at 5% level. Analysis of variance showed that main effect of mycorrhiza and humic acid were significant at 1% level and main effect of bacteria and interaction effect of mycorrhiza and bacteria were significant at 5% level for seed numbers of bean. Analysis of variance showed that main effect of bacteria and mycorrhiza and interaction effect of bacteria and mycorrhiza were significant at 1% level and interaction effect of bacteria and mycorrhiza were significant at 5% level on stem length. Analysis of variance showed that main effect of humic acid and mycorrhiza were significant at 1% level and main effect of bacteria and interaction effect of humic acid and bacteria were significant at 5% level for stem diameter. Analysis of variance showed the main effect of mycorrhiza was significant at 1% level and main effect of humic acid and interaction effect of bacteria and mycorrhiza and interaction effect of bacteria and humic acid and main effect of humic acid were significant at 5% level for the seed yield.
ConclusionAnalysis of variance of experiment treatments in this research showed that treatment applied had positive effect on agronomic properties of bean and humic acid could have direct and positive effect on plant root and shoot growth.